This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Objective: To understand the neural system underlying the expression of emotion in primates. Baseline brain metabolism, behavior, and physiological measures were characterized in preparation for surgery on subgenual Area 25, an area that has been implicated in depression. The findings from these studies will be highly relevant to humans, addressing the role of amygdala-orbitofrontal interactions in mediating normal emotion and psychopathology. This work used WNPRC Animal Services, surgery, pathology, operational services, and library and information services.